Content providers often publish content items in networked resources through online content management systems with the goal of having an end user interact with (e.g., click through) the content items and purchase a product or service offered by the content providers. Content providers traditionally have assigned credit for a conversion largely, if not entirely, to the last click prior to the conversion. Attribution is based on the principle that conversion decisions are the cumulative result of many interactions (e.g., clicks, impressions, video views, etc.) over time, and not just the last click prior to a conversion. Evaluating keywords based solely on the last click prior to conversion ignores the contributions made by keywords earlier in the conversion paths.